1. Field of the Invention
The present invention relates to a display panel, and particularly relates to design of a light-shielding layer in a display panel.
2. Description of Related Art
With great advance in techniques of manufacturing opto-electronics and semiconductor devices, flat panel displays have been vigorously developed. Among the flat panel displays, liquid crystal display (LCD) panels characterized by low operating voltage, free of harmful radiation, light weight and small and compact size gradually replace conventional CRT displays and have become mainstream displays. At this current stage, the LCD panels are developed towards full-colors, large sizes, high resolution and low costs. In order to achieve dull-color displaying, color filters are used in LCD panels. Currently, color filter substrates, color filter on array (COA) technology and array on color filter (AOC) technology are commonly used in fabrication. Take the COA technology as an example, since color filters are directly fabricated over thin film transistor array (TFT array), mis-alignment between the color filters and the TFT array can be minimized. Accordingly, the COA technology has been widely used in products.
FIG. 1 is a schematic cross-sectional view of a conventional LCD panel. Referring to FIG. 1, the conventional LCD panel 100 includes a TFT array substrate 110, a color filter layer 120 formed on the TFT array substrate 110, an opposite substrate 130 disposed above the TFT array substrate 110, and a liquid crystal layer 140 disposed between the TFT array substrate 110 and the opposite substrate 130. As shown in FIG. 1, the TFT array substrate 110 has a plurality of pixel electrodes 112 and the opposite substrate 130 has a black matrix 132. Area between the pixel electrodes 112 and edge of each pixel electrode 112 is shielded by the black matrix 132. Accordingly, light leakage occurred between the pixel electrodes 112 can be avoided. Since the black matrix 132 has taper X located above the pixel electrode 112, liquid crystal disclination resulted from the taper X may occurred and accordingly light leakage may occurred at edge of the black matrix 132. It is noted that in order to prevent color washout of LCD panels, each sub-pixel of the TFT array substrate 110 includes a main display unit and a sub-display unit, wherein display quality of the sub-display unit is significantly affected by light leakage resulted from the black matrix 132. Accordingly, how to avoid light leakage which is occurred at edge of the sub-display unit and resulted from the black matrix 132 is an important issue.